CAN Communication System (w/ Smart Key System)

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM (w/ Smart Key System): U1002: Lost Communication with Gateway Module (MS Bus)
U1002 - Lost Communication with Gateway Module (MS Bus)

DESCRIPTION

* The main body ECU stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the CAN MS bus.

* When the main body ECU receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN MS bus, the main body ECU determines that a malfunction exists.

* If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).





* *: w/ Power Back Door System

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

NEXT -- Continue to next step.

2. CHECK CAN BUS WIRE (CHECK MAIN WIRE FOR DISCONNECTION, CHECK BUS LINE FOR SHORT CIRCUIT)

(a) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





Result





C -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

B -- CHECK FOR SHORT IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR SIDE)
A -- Continue to next step.

3. CHECK FOR OPEN IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - CERTIFICATION ECU)

(a) Disconnect the D80 No. 3 junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

4. CHECK FOR OPEN IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - MAIN BODY ECU)

(a) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 3 JUNCTION CONNECTOR

5. CONNECT CONNECTOR

(a) Reconnect the D80 No. 3 junction connector.

NEXT -- Continue to next step.

6. CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU - NO. 3 JUNCTION CONNECTOR)

(a) Disconnect the D9 main body ECU (instrument panel junction block assembly) connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (MAIN BODY ECU - NO. 3 JUNCTION CONNECTOR)

OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

7. CONNECT CONNECTOR

(a) Reconnect the D80 No. 3 junction connector.

NEXT -- Continue to next step.

8. CHECK FOR OPEN IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - CERTIFICATION ECU)

(a) Disconnect the O23 CAN junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

9. CHECK FOR OPEN IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

(a) Disconnect the O24 CAN junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

OK -- REPLACE CAN JUNCTION CONNECTOR

10. CONNECT CONNECTOR

(a) Reconnect the O23 CAN junction connector.

NEXT -- Continue to next step.

11. CHECK FOR OPEN IN CAN BUS WIRE (CERTIFICATION ECU - CAN JUNCTION CONNECTOR)

(a) Disconnect the D40 certification ECU (smart key ECU assembly) connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO CERTIFICATION ECU (CERTIFICATION ECU - CAN JUNCTION CONNECTOR)

OK -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

12. CHECK FOR SHORT IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR SIDE)

(a) Disconnect the D80 No. 3 junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

13. CHECK FOR SHORT IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - TIRE PRESSURE MONITOR ECU)

(a) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

14. CHECK FOR SHORT IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - MAIN BODY ECU)

(a) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 3 JUNCTION CONNECTOR

15. CONNECT CONNECTOR

(a) Reconnect the D80 No. 3 junction connector.

NEXT -- Continue to next step.

16. CHECK FOR SHORT IN CAN BUS WIRE (TIRE PRESSURE MONITOR ECU)

(a) Disconnect the D33 tire pressure monitor ECU connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO TIRE PRESSURE MONITOR ECU (CANP, CANN)

OK -- REPLACE TIRE PRESSURE MONITOR ECU Removal

17. CONNECT CONNECTOR

(a) Reconnect the D80 No. 3 junction connector.

NEXT -- Continue to next step.

18. CHECK FOR SHORT IN CAN BUS WIRE (MAIN BODY ECU)

(a) Disconnect the D9 main body ECU (instrument panel junction block assembly) connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (CANP, CANN)

OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

19. CONNECT CONNECTOR

(a) Reconnect the D80 No. 3 junction connector.

NEXT -- Continue to next step.

20. CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

(a) Disconnect the O24 CAN junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)
OK -- Continue to next step.

21. CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - POWER BACK DOOR ECU)

NOTICE:
For vehicles without a power back door system, go to "Check for Short in CAN Bus Wire (CAN Junction Connector - Certification ECU)".

(a) Disconnect the O21 CAN junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

22. CHECK FOR SHORT IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - CERTIFICATION ECU)

(a) Disconnect the O23 CAN junction connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- CONNECT CONNECTOR

OK -- REPLACE CAN JUNCTION CONNECTOR

23. CONNECT CONNECTOR

(a) Reconnect the O21 and O24 CAN junction connectors.

NEXT -- Continue to next step.

24. CHECK FOR SHORT IN CAN BUS WIRE (POWER BACK DOOR ECU)

(a) Disconnect the O15 back door motor unit (power back door ECU) connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO POWER BACK DOOR ECU (MPX1, MPX2)

OK -- REPLACE BACK DOOR MOTOR UNIT (POWER BACK DOOR ECU) Removal

25. CONNECT CONNECTOR

(a) Reconnect the O21*, O23 and O24 CAN junction connectors.

*: w/ Power Back Door System

NEXT -- Continue to next step.

26. CHECK FOR SHORT IN CAN BUS WIRE (CERTIFICATION ECU)

(a) Disconnect the D40 certification ECU (smart key ECU assembly) connector.





Text in Illustration





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO CERTIFICATION ECU (CANH, CANL)

OK -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

27. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

(a) Connect the cable to the negative (-) battery terminal.

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.





Text in Illustration





(b) Disconnect the 1D, 1F, 1M, D7, D8 and D9 main body ECU (instrument panel junction block assembly) connectors.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)